JP-9-113310A shows a sensor system having a sensor unit, a processing unit and a communication line. The sensor unit includes a first sensor and a second sensor. The first sensor detects a first physical quantity and outputs a first detection signal. The second sensor detects a second physical quantity and outputs a second detection signal. The processing unit receives the first and second signals from the sensor unit through the communication line through which communication signals are transmitted in a form of bit-sequence.
The sensor unit includes a selector (switching circuit) selecting a detection signal which should be outputted. This selector is operated based on a switching command signal which is transmitted from the processing unit with the communication signals. The selected detection signal is converted into a bit-sequence by an A-D converting circuit and is transmitted to the processing unit with the communication signal.
However, in the above-mentioned conventional configuration, since the detection signal is transmitted from the sensor unit to the processing unit with the communication signal in a form of a bit string, a transmission speed of the detection signal is limited at a specified value.